669637049 has 2 divisors, whose sum is σ = 669637050. Its totient is φ = 669637048.

The previous prime is 669637043. The next prime is 669637069. The reversal of 669637049 is 940736966.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 516743824 + 152893225 = 22732^2 + 12365^2 .

It is a cyclic number.

It is not a de Polignac number, because 669637049 - 2²⁴ = 652859833 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 669636988 and 669637006.

It is not a weakly prime, because it can be changed into another prime (669637043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334818524 + 334818525.

It is an arithmetic number, because the mean of its divisors is an integer number (334818525).

Almost surely, 2^669637049 is an apocalyptic number.

It is an amenable number.

669637049 is a deficient number, since it is larger than the sum of its proper divisors (1).

669637049 is an equidigital number, since it uses as much as digits as its factorization.

669637049 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1469664, while the sum is 50.

The square root of 669637049 is about 25877.3462511132. The cubic root of 669637049 is about 874.8759765441.

The spelling of 669637049 in words is "six hundred sixty-nine million, six hundred thirty-seven thousand, forty-nine".